Kubb is situational, but I can say that you never want to place a kubb in front, then add kubbs behind. Hitting a kubb with a kubb is equivalent to a punishment kubb. The best you can get is 1 kubb with 1 baton.
If I have two kubbs, most times I go with a flat drill halfway between the king and the centerline pin. Put the first one 15 cm back from the centerline, and try to pop the second kubb right on the line so it's forced in. Easier said than done. You don't want the opponents to have a parallel option for tipping them up, so a flat drill gets you closer to that "snakey" vertical alignment. Vertical alignment also helps with getting your facing flat, so the kubb will roll back for the double.
I don't go for the corners with 1 or 2. I'd hate for the opponents to put a kubb right behind that centerline pin.
More than 2, go for the corner. Drop your first one in with a slight goofy cut that just pops in directly behind the centerline pin. After that first throw, and seeing where it lands, then it is all situational. "Be the artist" as Eric A would say.